> ## Documentation Index
> Fetch the complete documentation index at: https://docs.supertoneapi.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Release notes

> Latest updates and changes to the Supertone API.

<Update label="2026-06-16" description="CLI & MCP">
  ## Command-line interface and MCP server

  Two new ways to use Supertone TTS beyond the SDKs: a terminal CLI and an MCP server for AI agents. Both wrap the same Text-to-Speech API.

  ### What's new

  1. **Supertone CLI**
     * Synthesize from strings, files, or stdin; stream to your speakers; batch whole directories; and manage voices, usage, and credits — all from the terminal.
     * `pip install supertone-cli`
     * See [CLI](/en/docs/developer-tools/cli).

  2. **Supertone MCP server**
     * Exposes the TTS API as composable [Model Context Protocol](https://modelcontextprotocol.io) tools, so AI agents in Claude, Cursor, Claude Code, VS Code, and Windsurf can discover voices, estimate cost, clone voices, and synthesize speech.
     * `uvx supertone-mcp`
     * See [MCP](/en/docs/developer-tools/mcp).
</Update>

<Update label="2026-05-19" description="v1.4.0">
  ## New TTS model: `supertonic_api_3`

  The Supertone API now supports `supertonic_api_3`, the next-generation successor to `supertonic_api_1`. It keeps the ultra-low latency profile of its predecessor while dramatically improving speech stability and expanding language coverage.

  ### What's new

  1. **`supertonic_api_3` — Successor to `supertonic_api_1`**
     * Inherits the ultra-low latency profile of `supertonic_api_1`
     * **Significantly improved speech stability** — far fewer pronunciation and reading errors
     * Trained differently from the open-weights Supertonic 3 release, so this is a distinct model
     * Supports **31 languages**: `en`, `ko`, `ja`, `ar`, `bg`, `cs`, `da`, `de`, `el`, `es`, `et`, `fi`, `fr`, `hi`, `hr`, `hu`, `id`, `it`, `lt`, `lv`, `nl`, `pl`, `pt`, `ro`, `ru`, `sk`, `sl`, `sv`, `tr`, `uk`, `vi`
     * Voice settings: `speed` only (same as `supertonic_api_1`)

  2. **`supertonic_api_1` is now the legacy supertonic model**
     * Still available for existing integrations
     * New projects should use `supertonic_api_3`

  3. **Model selection expanded** — TTS requests now accept `sona_speech_2`, `sona_speech_2_flash`, `supertonic_api_3`, `supertonic_api_1`, and `sona_speech_1`.

  See [Models](/en/docs/core-concepts/models) for full comparison and selection guidance.
</Update>

<Update label="2025-12-08" description="v1.3.0">
  ## New TTS models: `sona_speech_2`, `sona_speech_2_flash`, and `supertonic_api_1`

  The Supertone API now supports three new speech synthesis models, expanding multilingual capabilities and offering more flexible generation options.

  ### What's new

  1. **`sona_speech_2` — Multilingual flagship**
     * Supports **23 languages**
     * Improved speech quality and stability
     * Supports `include_phonemes` and `normalized_text`
     * Voice settings: all parameters except `subharmonic_amplitude_control`

  2. **`sona_speech_2_flash` — Low-latency variant**
     * Same 23 languages as `sona_speech_2`
     * Optimized for lower latency
     * Voice settings: `pitch_shift`, `pitch_variance`, `speed`, `duration`

  3. **`supertonic_api_1` (beta) — Lightweight low-latency model**
     * Supports `en`, `ko`, `ja`, `es`, `pt`
     * Designed for fastest inference and simplest setup
     * Voice settings: `speed` only

  4. **Model selection expanded** — TTS requests now accept `sona_speech_2`, `sona_speech_2_flash`, `supertonic_api_1`, and `sona_speech_1`.

  See [Models](/en/docs/core-concepts/models) for full comparison and selection guidance.
</Update>

<Update label="2025-07-31" description="v1.2.0">
  ## Custom voices and streaming TTS (beta)

  Several new features have been added to the Supertone API. In this release, **Preset Voices** and **Custom Voices** have been separated, and voice cloning via API is now supported. A beta version of streaming TTS has also been released.

  ### What's new

  1. **Preset vs custom voice separation**
     * Preset voices are designed and provided by Supertone.
     * Custom voices are clones registered and managed by the customer.
     * New endpoints under `/v1/custom-voices/...` for managing customer-owned voices.

  2. **Voice cloning via the API**
     * Voice cloning, previously only available in Supertone Play, is now supported via API.
     * See [Create cloned voice](/en/api-reference/endpoints/create-cloned-voice).

  3. **Streaming TTS (beta)**
     * A beta version of the streaming TTS API is available, ideal for real-time applications such as AI chatbots and character-based chat.
     * See [Stream speech](/en/docs/text-to-speech/stream-speech).
</Update>

<Update label="2025-05-28" description="v1.1.0">
  ## Supertone API grand open

  The Supertone API has officially launched after completing its closed beta phase. This release features a complete overhaul of the service structure and API usability, evolving into a more intuitive and scalable voice generation platform through integration with Play and unification of the voice system.

  <Frame>
    <img src="https://mintcdn.com/supertone-b89202c8/0gAKILFZFHulmmA8/images/supertone-api-grand-open.png?fit=max&auto=format&n=0gAKILFZFHulmmA8&q=85&s=1a8c108b3cc1569bd3b87aacc44fc0b1" alt="" width="2118" height="1380" data-path="images/supertone-api-grand-open.png" />
  </Frame>

  ### Major changes

  1. **Voice ID structure redesign**
     * Changed from `{character-language-style}` combination → unified to **character-based `voice_id`**.
     * `language` and `style` parameters moved into the request body for flexible calling.

  2. **New TTS model**
     * Replaced `pro` and `turbo` → unified into a single `sona_speech_1` model.
     * Improved speech quality; text length limit increased from 200 to **300 characters**.

  3. **Cloned voice API support**
     * Cloned voices created in Play can now be called via the API.
     * Automatic integration within the same account, with permission-based security.

  4. **Play and pricing integration**
     * API usage applies Play's credit system directly.
     * Shared credits and unified billing — no separate pricing plans.

  5. **Enhanced voice search**
     * Filtering and exploration via `GET /voices` and `GET /voices/search`.
     * Each voice exposes supported languages, styles, and samples.

  6. **Predict Duration API**
     * Estimate speech length before generation — no credits deducted.

  7. **New user guide and documentation**
     * Practical documentation including Quickstart, Voice Selection, Error Handling, and FAQ.
     * Complete documentation renewal focused on the Play ↔ API integration flow.
</Update>

<Update label="2025-01-23" description="v1.0.1">
  ## Voice search update

  New search features make it easier to find the voices you want.

  ### What's new

  * New endpoint for searching voices with filters and keywords.
  * Filter by language, gender, age, and use case.
  * Keyword search across voice names and descriptions.
  * Page-based pagination for large result sets.

  See [Search voices](/en/api-reference/endpoints/search-voices).
</Update>

<Update label="2024-12-23" description="v1.0.0">
  <Frame>
    <img src="https://mintcdn.com/supertone-b89202c8/0gAKILFZFHulmmA8/images/supertone-api-landing-page.png?fit=max&auto=format&n=0gAKILFZFHulmmA8&q=85&s=1e13e66b7e2d50b36c928603b7986db5" alt="" width="2880" height="2160" data-path="images/supertone-api-landing-page.png" />
  </Frame>

  ## Supertone API closed beta launch

  Welcome to the **Supertone API** closed beta — Supertone's voice AI technology as a service.

  ### Key features

  1. Text-to-speech voice synthesis service.
  2. Voice list inquiry and usage check APIs.

  ### Endpoints

  * [List voices](/en/api-reference/endpoints/list-voices) — retrieve available voices.
  * [Create speech](/en/api-reference/endpoints/text-to-speech) — convert text to speech.
  * [Get voice usage](/en/api-reference/endpoints/get-voice-usage) — check API usage.

  ### Getting started

  1. Sign up at [console.supertoneapi.com](https://console.supertoneapi.com).
  2. Apply for closed beta participation.
  3. Issue an API key from the console.
  4. Integrate and use the API.

  ### Console features

  * API key issuance and management.
  * Minute-based API usage monitoring.

  For more details, refer to the [docs](/en/docs/overview).
</Update>